JPH0357507A - Method for controlling meandering of plate under rolling - Google Patents

Abstract

PURPOSE:To improve the quality of produce by controlling a meandering quantity in an allowable range based on a wedge quantity and meandering quantity, etc. of a slab, operating a leveling quantity to minimize the chamber quantity of the slab and controlling the meandering quantity of the slab by sending the leveling quantity to screw-down control device. CONSTITUTION:The wedge quantity and meandering quantity of the slab 2 which is entered in a rolling mill 1 and the leveling offset quantity of the rolling mill 1 is determined. Based on each determined quantity, the leveling quantity of the rolling mill 1 to control the meandering quantity of the slab 2 in the allowable range and to minimize the chamber quantity of the slab 2 is operated with use of an operation part 4b for optimum leveling quantity with optimization. That leveling quantity is fed to a control device 1c for the screw- down system of the rolling mill 1 and control is performed. And the meandering quantity of the slab 2 is controlled. By this method, the rolling troubles in the rolling process and the next process are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling both the meandering state and the camber during rolling of a plate material.

[Prior Art] When rolling a plate material, a phenomenon may occur in which the plate material escapes from the center of the mill during rolling. When this plate escape phenomenon occurs, the plate material hits the side guide and squeezes, causing damage to the roll and a difference in thickness between the left and right width edges of the plate.
This will lead to deterioration of product quality and decreased productivity.

This phenomenon tends to occur when the plate material goes through, that is, when there is no tension on the entry side.

Conventional control means include means for measuring the meandering equivalent amount and manipulating the leveling amount proportional to that amount, and means for manipulating the leveling amount corresponding to the sum of the meandering equivalent amount and the differential value. . Furthermore, as means for measuring the amount of meandering, methods have been proposed, such as means for measuring the difference in load between the left and right sides of the rolling mill, and means for measuring the movement of the left and right width edges using sensors.

On the other hand, as a means to control the amount of camber of the plate material, conventionally used is a method of installing a camber meter on the entrance side of the rolling mill to measure the amount of camber of the plate material entering the rolling mill and change the leveling amount. . This method is mainly applied to thick plate rolling.

[Problems to be Solved by the Invention] Incidentally, the amount of meandering and the amount of camber influence each other, and as in the conventional control means described above, the focus is only on suppressing the amount of meandering or the amount of camber. If one is controlled, the other will be sacrificed. Particularly, when hot rolling is performed in a region where the thickness of the sheet material is thin, the contradiction between the two controls increases.

The present invention aims to solve the above-mentioned problems, and is a meandering control method during sheet rolling that improves product quality by simultaneously suppressing meandering and camber of the rolled sheet material. The purpose is to provide

[Means for Solving the Problems] In order to achieve the above object, the meandering control method during plate rolling of the present invention includes: (1) controlling the wedge amount and meandering amount of the plate material entering the rolling mill and the leveling of the rolling mill; (2) Calculate the amount of leveling of the rolling mill that suppresses the meandering amount of the plate material within an allowable range and minimizes the amount of camber of the plate material based on each of the obtained amounts by an optimization method; and (2) the meandering amount of the plate material is controlled by sending the leveling amount to a rolling system control device of the rolling mill and controlling the rolling mill.

[Function] In the meandering control method during plate rolling of the present invention described above, first,
The wedge amount and meandering amount of the plate material and the leveling offset amount of the rolling mill are directly measured or indirectly determined, and based on each value, the amount of meandering of the plate material is suppressed within the allowable range and the amount of camber of the plate material is minimized. The leveling amount of the rolling mill is calculated by an optimization method. Then, based on this leveling amount, the rolling mill is controlled by the rolling system control device, and the meandering amount of the plate material is suppressed and controlled.

[Embodiments of the Invention] Hereinafter, a meandering control method during plate rolling as an embodiment of the present invention will be explained with reference to the drawings. Fig. 1(a) shows an apparatus structure for carrying out the method of the present invention. Block Diagram,
The construction drawing (b) is a block diagram showing the main parts of the above-mentioned equipment in detail. In these Figures 1-3-(a) and (b), 1 is a rolling mill, and la is a rolling mill 1. Rolling roll 1b is a rolling device and rolling system control device 1
c to perform leveling adjustment in the rolling mill 1. In addition, 2 is a rolled material (plate material) that enters the rolling mill 1 and is rolled, and 3 is a sensor for detecting the difference in left and right rolling weight in the rolling mill 1A at the front stage of the rolling mill J, which is subjected to leveling control to execute meandering control. A load cell 4 is a computer that executes calculations (described later) and control according to the method of the present invention, and this computer 4 calculates the meandering amount Δy of the rolled material 2 and the exit side wedge amount ΔH based on the detection signal from the load cell 3. It is provided with a meandering amount/outside wedge amount calculating section 4a for calculating the amount of meandering and an optimum leveling amount calculating section 4b. The optimum leveling amount calculation unit 4b calculates the calculated amounts Δy, ΔH and the leveling offset 1 to amount Δ of the rolling mill 1 inputted from the outside.
Based on So, the meandering amount Δy of the rolled material 2 is suppressed within the allowable range, and the exit side camber amount (camber curve 1) l/ρ of the rolled material 2 is controlled according to the calculation formula described later and the flow shown in FIG.
The leveling amount ΔS of the rolling 41l1 that minimizes 2 is calculated by the optimal 4-1 conversion method and sent to the rolling mill 1's rolling system hJ Goso WIC.

Next, the arithmetic expressions used in the computer 4 will be explained. First, the wedge amount on the entry side of the rolled material 20 (the difference in plate thickness between the left and right sheet width ends of the rolled material 2) is ΔH(t), and the off-center amount is Δy.
o(t), meandering amount Δy (t), leveling offset amount of rolling mill 1 ΔSo, leveling amount operated from now on ΔS (t), exit side wedge amount of rolled material 2 Δh, difference between left and right rolling wheels. Assuming Δr, this left and right rolling reduction rate difference 8r is given by the following equation (1).

Δr(t)=AHΔH(t)+AyΔy(t) As
{ΔS. +ΔS(t)} = (1) Here, Al++
AV+AS is a positive coefficient, Δr and ΔH are positive for increasing on the working side, Δy is positive for relief on the rolling side, and ΔS is positive for opening on the working side.

Further, the meandering amount Δy is given by the following equation (2).

Δy=KEf:4+Δr dtdt+Δy. −
(2) The exit camber curvature 1/ρ2 is expressed by the following equation (3).

1/ρ2=1/ρ1/λ2+αΔr...(3)
Here, ρ1 is the entrance curvature, λ is the elongation rate, and α is the coefficient.

? , to control the meandering amount Δy(t.)=Δ3/A at time 1=1■ and to obtain the leveling amount ΔS that minimizes the exit camber curvature l/ρ2, use the following formula (4). What is necessary is to calculate the leveling amount that minimizes the evaluation function G shown in FIG.

G=Kf(1/ρ.)2dt+λ{Δy(td)−Δy
A}...(4) Also, ΔH(t), Δy o
(t), ΔS(t), ΔS o(t) are expressed by the following formula (5)
It is approximated by

・-・(5) Substituting this equation (5) into equations (2) and (1), we get equation (6
), as shown in equation (7).

7−ΔSo2 KpAs 2 't (6) Also, by substituting equations (3) and (5) into equation (4) and rearranging, the evaluation function G is as shown in equation (8) below. become.

R ...(8) and, A condition that minimizes such evaluation function G is The matter is δG / a Cp" 0 ・(9) aG/a　λ=○ (10) is given by

That is, From equations (8) and (9), 9 -10 Then, From equations (8) and (10), becomes.

In order to obtain the optimum leveling amount ΔS, the optimum leveling Jl calculation section 4b executes calculations according to the procedure shown in FIG. First, the input side wedge amount ΔH and off-center amount Δyo of the rolled material 2 calculated by the calculation unit 4a based on the detection results from the load cell 3 and the leveling offset amount ΔSo of the rolling mill 1 are calculated by the optimum leveling amount calculation unit 4b.
(Step Sl). Then, the first @-th calculation is dL-bL (step S2), and the second @-th calculation is dL-bL. cL is calculated from the following equation (l3).

111 d, bol ? 1=b■, Here, the constant K is a weighting coefficient applied to camber.

In conclusion, by solving the simultaneous linear equations of equations (11) and (12), the optimal coefficient cL can be found (step S3)
. Using the obtained cL, find the left and right pressure difference Δr from equation (1), substitute this into equation (2) to find the meandering amount Δy, and from this Δy find the coefficient dL using equation (l3). Step S4), from equations (n) and (12), coefficient C
Solve the simultaneous equations with and as the unknown. If such calculations are repeated for 2 to 3 solutions, the coefficient CI. converges. By substituting the coefficient cL obtained in this way into the third equation of equation (5), the optimum leveling amount ΔS is calculated, and the calculation unit 4b outputs this to the rolling system control device 1c (step S5).

12? As a result, Δy = ΔYA at time 1 = 1
The optimum leveling amount ΔS of the rolling mill 1 that minimizes the amount of camber of the rolled material 2 is calculated by the optimization method, and the rolling mill 1 is controlled by the rolling system control device 1c based on this leveling amount ΔS. The meandering amount is suppressed and controlled.

The specific effects of the apparatus of this embodiment are shown in FIGS. 3 to 5. Here, the entrance side plate thickness H = 1.43 mm, the exit side plate thickness h
=i. 29mm, plate width W=IOOOmm, rolling roll 1
The simulation results in a hot rolling finishing mill are shown when the diameter D of a is 800 mm. The disturbance at this time is ΔH = 0.02t''+0.01t+0.02(t
:see), entry side meandering amount Δy = 5-45t+50t
” (mm). Fig. 3 shows the case where the control method of the present invention is used, Fig. 4 shows the case where the conventional control means is used, and Fig. 5
The figure shows the case where only the amount of camber is minimized. As shown in FIG. 5, when only the camber amount is controlled to be minimized, the meandering amount Δy becomes larger and larger. Also. As shown in FIG. 4, in the conventional means, even if the meandering amount Δy is suppressed, the camber amount 1/ρ becomes large (the camber amount is on the order of 10').

On the other hand, as shown in FIG. 3, it can be seen that according to the means of the present invention, the amount of camber l/ρ can be minimized while suppressing the amount of travel Δy (the amount of camber is on the order of 10 inches).

As described above, according to the meandering control method of this embodiment, it is possible to reliably suppress the meandering of the rolled material 2 within the permissible range during plate rolling, and at the same time, it is possible to suppress the exit side camber amount of the rolled material 2. Therefore, rolling troubles in the rolling process and subsequent processes can be significantly reduced, and product quality can be greatly improved.

[Effects of the Invention] As detailed above, according to the meandering control method during plate rolling of the present invention, the meandering amount of the plate material is allowed based on the wedge amount and meandering amount of the plate material and the leveling offset amount of the rolling mill. The amount of leveling that minimizes the amount of camber of the plate material while keeping it within the range is calculated using an optimization method, and the rolling mill is controlled based on this leveling amount, so it is possible to reliably suppress the meandering of the plate material within the allowable range. At the same time, it is possible to suppress the amount of camber in the plate material, significantly reducing rolling troubles in the rolling process and the next process, and significantly improving product quality.

[Brief explanation of drawings]

FIG. 1(a) is a block diagram showing the structure of an apparatus for implementing a meandering control method during plate rolling as an embodiment of the present invention, and FIG. 1(b) is a detailed view of the main parts of the apparatus. The block diagram shown in FIG. 2 is a flowchart 1 for explaining the operation of the apparatus described in 2, and FIGS. 3 to 5 are graphs for explaining the effects of the above embodiment. In the figure, 1-rolling mill, 1a one rolling roll, 1b one rolling device, 1. c- Rolling system control device, 21 Rolled material (plate material)
, 3-load cell, 4-computer, 4a meandering amount/output side weave amount calculation section, 4b-optimum leveling amount calculation section.

Claims (1)

[Claims] The amount of wedge and meandering of the plate material entering the rolling mill and the leveling offset amount of the rolling mill are determined, and based on each of the determined amounts, the amount of meandering of the plate material is determined to be within an allowable range. by calculating, by an optimization method, a leveling amount of the rolling mill that minimizes the amount of camber of the plate material, and sending the leveling amount to a rolling system control device of the rolling mill to control the rolling mill. A meandering control method during plate rolling, characterized by controlling the meandering amount of the plate material.